ML17300A764

Special Rept 2-SR-87-005:on 870308,high-range Noble Gas Activity Monitor RU-146 Inoperable for Greater than 72 H. Caused by Random Cycling Alarms to Microcomputer Software. Plant Change Request PCR 87-13-SQ-020 Initiated

ML17300A764
Person / Time
Site:	Palo Verde
Issue date:	04/03/1987
From:	Haynes J ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
192-00177-JGH-T, 192-177-JGH-T, 2-SR-87-005, 2-SR-87-5, NUDOCS 8704220084
Download: ML17300A764 (6)

Text

REGULATORS NFORNATIQN DISTR IBUTIQN S El'1 (R IDS)

ACCESSION NBR: 8704220084 DOC. DATa: 87/04/03 NOTARIZED: NO DOCKET FACIL STN-50-529 Palo Vev de Nuclear Station> Uni 2> Av i zona Pub t li 05000529 AUTH. NAME AUTHOR AFF IL ATION I (former IM Av izona Public Sev v HAYNES, J. Q. Av izona Nucleav Pouev Prospect RECIP. NAI'IE RE C I P I F NT AFF I L I AT I OiN MARTIN> S. B. Region 5> Of fice of Director BUB JECT: Special Rept 2-SR-87-005: on 870308> high v ange noble gas activitll monitor (RU-}46) inoperable for gv eatev'han 72 h.

Caused bg v andom cycling alarns to micro computer soft4!are.

Plant Change Request PCR S7->3-SQ-020 i niti ated.

DISTRIBUTION CODE: IE22D COPIEB RECEIVED: LTR ENCL SIZE:

TITLE: 50. 73 Licensee Event Repov t (LER)> Incident Rpt> etc.

NOTES: Btandardi zed plant. N. Davi s> NRR: }C!1. 05000529 REC IP IENT COPIES RECIPIENT COP IES ID CODE/NAI'IE LTTR ENCL ID CODE /NAI'IE LTTR ENCL PD5 LA 1 1 PD5 PD 1 LIClTRA> E 1 1 DAVIB> N 1 1 INTERNAL: ACRB NICHELSON 1 1 ACRS NOELLER 1 1 AEOD/DOA AEOD/DSP/ROAB 2 2 AEOD/DBP/TAPB 1 AEOD/DSP/TPAB 1 1 NRR/ADT 1 t::RR/DEBT/ADE 0 NRR/DEST/ADB 0 I'!RR/DEBT/CEB 1 NRR/DEBT/EL 8 1 t!RR /DEBT/ I CSB 1 1 NRR/DEBT/MEB 1 ts! RR /DEST/MTB } 1 NRR/DEST/PSB 1 ts!RP/DEBT/RSB 1 NRR/DEBT/BGB 1 1 >4!RR/DLPG/HFB 1 NRR/DLPG/GAB 1 t!RR/DOEA/EAB 1 1 NRR/DREP/EPB 1 iNRR/DREP/RAB 1 1, NRR/DREP/RPB 2 2 ~jR 8/ I LR8 1 1 NRR/Pl'IAS/PTBB 1 REC FIL 02 1 1 RES SPEIS, T 1 1 FILE 01 1 EXTERNAL: EQ8(G QROH> N 5 5 H ST LOBBY WARD 1 LPDR 1 tuRC PDR 1 1 NSIC HARRIS> J tt!SI C NAYS> G 1 TOTAL NUI'1BER OF COP IEB REQUIRED: LTTR 45 ENCL 43

1 I"-"'-)VER

~ W( ~

Arizona Nuclear Power Project P.O,BOX 52034 ~ PHOENIX, ARIZONA 8507$4Q4 I',O[~g O tII~

192-00177MGQIIDRB fRSP April 3, 1987 Mr. John B. Martin, Regional Administrator Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Region V 1450 Maria Lane, Suite 210 Walnut Creek, CA 94596-5368

Subject:

Palo Verde Nuclear Generating Station Unit 2 Docket No. STN 50-529 (License NPF-51)

Special Report 2-SR-87-005 File: 87-020-404

Dear Mr. Martin:

Attached please find a Special Report 2-SR-87-005 prepared and submitted pursuant to Technical Specifications 3.3.3.'9 and 6.9.2. This report discusses a Radiation Monitoring Unit Inoperable Greater than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

If you have any questions, please contact Tom Bradish, Compliance Supervisor at (602) 932-5300, Ext. 6936.

Very truly yours,

.c'./7-~

J. G. Haynes Vice President Nuclear Production JGH/TRB/ESP/cld Attachment cc: 0. M. DeMichele (all w/a)

E. E. Van Brunt, Jr.

R. P. Zimmerman R. C. Sorenson E. A. Licitra A. C. Gehr INFO Records Center 8704p@0084 87040>

PDR ADOCK 05000529 PDR gg2'

PALO VERDE NUCLEAR GENERATING STAT Radiation Monitoring Unit Inoperable for Greater Than 72 Hours License No. NPF-51 Docket No. STN 50-529 Special R'eport No. 2-SR-87-005 This Special Report is being submitted pursuant to Technical Specification (T.S.)

3.3.3.9 ACTION 42b and T.S. 6.9.2 to report an event in which a high range noble gas activity monitor (RU-146) was inoperable for greater than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> limit for operability was exceeded at approximately 2252 MST on March 8, 1987.

Pursuant to T.S. 3.3.3.9 ACTION 42a the Preplanned Alternate Sampling Program was initiated to monitor the plant ventilation system.

At approximately 2252 MST on March 5, 1987, Palo Verde Unit 2 was in Mode 3 (HOT STANDBX) for a surveillance outage when RU-146 was taken out of service to allow the replacement of eraseable programmable read only memory (EPROM) chips in the micro computer, as a system upgrade. To return RU-146 to service, 36ST-9ZZ04 (Radiation Monitoring Quarterly Functional Test) was initiated. In accordance with 36ST-9ZZ04, alarms wer'e initiated to test the monitor. These alarms should have been continuous, however, the alarms would cycle off and then on again at random intervals. This problem only occurred at the radiation monitorinig system mini computer, all other loop indications were normal.

Troubleshooting conducted under an authorized work document attributed the cause of the random cycling alarms to the micro computer software. As corrective action, Plant Change Request (PCR) 87-13-SQ-020 was initiated to correct the micro computer software.

As additional corrective action, an Engineering Evaluation Request (EER) 87-SQ-101 was initiated to address the potential of similar cases in other monitors encompassing all three units. The disposition of this EER determined that all effected monitors are operable since these cycling alarms do not affect the monitors'bility to detect radiation. This software problem exists in this software revision, as well as previous software revisions.

To return RU-144 to service, Quarterly Functional Test (36ST-9SQ04) was successfully performed. The monitor was declared operable at 1413 on March 16, 1987. The monitor was unavailable for 10 days 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> and 21 minutes.

A'@bi 0

I